Hansen Solubility Parameters (HSP) helps to predict the compatibility of ingredients.

It is based upon the “like seeks like” principle. It splits an ingredients interactions into three parameters :
- δD (Dispersion force interactions)
- δP (Polar forces interactions)
- δH (Hydrogen bond force interactions).

If ingredients have matching HSP’s (distance=0) then they will be completely compatible. If there is a small distance between them then they are predicted to have good but not perfect compatibility. As the HSP distance gets larger the ingredients will become more incompatible.

In general, ingredients having an HSP distance below 2 will have good compatibility. Between 2 and 4, you will have medium compatibility. Above 4, you will have limited to no compatibility.

Most HSP values used to calculate the distance are estimates. Information provided below is to be used as an indication of compatibility.